Concentrator photovoltaics (CPV) is a promising technology for renewable electricity generation in sunny environments. CPV uses relatively inexpensive, efficient optics to concentrate sunlight onto solar cells, thereby reducing the cost requirements of the semiconductor material and enabling the economic use of the most efficient cells, for example multi junction solar cells. This high efficiency at reduced costs, in combination with other aspects, makes CPV among the most economical renewable solar electricity technology in sunny climates and geographic regions.
Concentrator photovoltaic solar cell systems may use lenses or mirrors to focus a relatively large area of sunlight onto a relatively small solar cell. The solar cell can convert the focused sunlight into electrical power. By optically concentrating the sunlight into a smaller area, fewer and smaller solar cells with greater conversion performance can be used to create more efficient photovoltaic systems at lower cost.
For example, CPV module designs that use small solar cells (for example, cells that are smaller than about 4 mm2) may benefit significantly because of the ease of energy extraction from such cells. The superior energy extraction characteristics can apply to both usable electrical energy and waste heat, potentially allowing a better performance-to-cost ratio than CPV module designs that use larger cells. To increase or maximize the performance of concentrated photovoltaic systems, some existing CPV systems can be mounted on a tracking system that aligns the CPV system optics with a light source (typically the sun) such that the incident light is substantially parallel to an optical axis of the concentrating optical elements, to focus the incident light onto the photovoltaic elements.
Some designs and processes for making micro-concentrator solar modules are described in U.S. Patent Application Publication No. 2008/0121269. Also, some methods for making concentrator photovoltaic modules, receivers, and sub-receivers are described in U.S. Pat. No. 7,972,875 and U.S. Patent Application Publication No. 2010/0236603. Some space-based power generation is described in U.S. Pat. Nos. 5,498,297; 4,069,812; 4,711,972; 6,031,179; 6,075,200; and 8,974,899.